b. RES-1 applies to a unit that has been exposed to nuclear radiation. The unit has received a dose
greater than 0 cGy but less than or equal to 70 cGy.
c. RES-2 applies to a unit that has received a significant, but not dangerous, dose of radiation. The
unit has received a dose greater than 70 cGy but less than or equal to 150 cGy. If the situation permits,
units in this status should be exposed less frequently and to smaller doses than the units in RES-1 or RES-
d. RES-3 applies to a unit that has already received a dose of radiation greater than 150 cGy.
Consequently, further exposure is dangerous. This unit should be exposed only if unavoidable, because
additional exposure in the immediate future would result in sickness and probably some deaths.
1-7. Degree-of-Risk Concept. The degree-of-risk concept provides guidance to the commander in
establishing the OEG. It also assists in minimizing the number of casualties from nuclear radiation. The
commander can establish the OEG on the degree-of-risk criteria.
a. There are three degrees of risk: negligible, moderate, and emergency. Each of these can be
applied to radiation hazards resulting from enemy or friendly weapons, or both. It can also be applied to
initial nuclear radiation resulting from planned friendly supporting fires.
b. Degrees of risk are defined in terms of the expected response of personnel who are exposed to
nuclear radiation. These responses are expressed as a percentage of casualties or performance
degradation. The radiation aspects of degrees of risk are as follows:
(1) Negligible risk. Troops receiving a negligible-risk dose will not experience more than
2.5 percent incidence of vomiting. This dose will cause no casualties. The negligible risk dose is 50 cGy
for units with no previous dose (RES-0 units). It will be less for previously exposed units. A negligible
risk is acceptable in any situation in which the use of friendly nuclear weapons is desirable. Negligible
risk should not be exceeded unless significant advantage will be gained.
(2) Moderate risk. Troops receiving a moderate risk will not experience more than a 5
percent incidence of vomiting. This dose will cause no casualties. A moderate dose rate is 70 cGy for
units with no previous dose. It will be less for previously exposed units. A moderate risk is considered
acceptable in friendly close-support operations; for example, operations will create a gap in enemy
forward positions or halt an enemy attack. Moderate risk should not be exceeded if troops are expected to
operate at full efficiency after a friendly burst.
(3) Emergency risk. Troops receiving an emergency risk dose will experience no more than
5 percent casualties. However, incidence of vomiting may be higher. An emergency risk dose is 150 cGy
for units with no previous dose. It will be less for previously exposed units. An emergency risk should
be accepted only when it is absolutely necessary. It should be exceeded only in extremely rare situations
that might be called "disaster situations." No attempt is made to define disaster situations. The
commander must determine these extremely rare situations for himself and decide which criteria are
appropriate to use in attempting to salvage them.
NOTE: The commander at division or brigade level will determine the degree of risk. When this
determination reaches battalion level, conversion is made to the number of cGy that are acceptable
for the operation.